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+------------------------------------------------------------------------------
+-- --
+-- GNAT RUN-TIME COMPONENTS --
+-- --
+-- G N A T . M B B S _ F L O A T _ R A N D O M --
+-- --
+-- S p e c --
+-- --
+-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
+-- --
+-- This specification is derived from the Ada Reference Manual for use with --
+-- GNAT. The copyright notice above, and the license provisions that follow --
+-- apply solely to the contents of the part following the private keyword. --
+-- --
+-- GNAT is free software; you can redistribute it and/or modify it under --
+-- terms of the GNU General Public License as published by the Free Soft- --
+-- ware Foundation; either version 3, or (at your option) any later ver- --
+-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
+-- --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception, --
+-- version 3.1, as published by the Free Software Foundation. --
+-- --
+-- You should have received a copy of the GNU General Public License and --
+-- a copy of the GCC Runtime Library Exception along with this program; --
+-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
+-- <http://www.gnu.org/licenses/>. --
+-- --
+-- GNAT was originally developed by the GNAT team at New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc. --
+-- --
+------------------------------------------------------------------------------
+
+-- The implementation used in this package was contributed by
+-- Robert Eachus. It is based on the work of L. Blum, M. Blum, and
+-- M. Shub, SIAM Journal of Computing, Vol 15. No 2, May 1986. The
+-- particular choices for P and Q chosen here guarantee a period of
+-- 562,085,314,430,582 (about 2**49), and the generated sequence has
+-- excellent randomness properties. For further details, see the
+-- paper "Fast Generation of Trustworthy Random Numbers", by Robert
+-- Eachus, which describes both the algorithm and the efficient
+-- implementation approach used here.
+
+-- Formerly, this package was Ada.Numerics.Float_Random. It is retained
+-- here in part to allow users to reconstruct number sequences generated
+-- by previous versions.
+
+with Interfaces;
+
+package GNAT.MBBS_Float_Random is
+
+ -- Basic facilities
+
+ type Generator is limited private;
+
+ subtype Uniformly_Distributed is Float range 0.0 .. 1.0;
+
+ function Random (Gen : Generator) return Uniformly_Distributed;
+
+ procedure Reset (Gen : Generator);
+ procedure Reset (Gen : Generator; Initiator : Integer);
+
+ -- Advanced facilities
+
+ type State is private;
+
+ procedure Save (Gen : Generator; To_State : out State);
+ procedure Reset (Gen : Generator; From_State : State);
+
+ Max_Image_Width : constant := 80;
+
+ function Image (Of_State : State) return String;
+ function Value (Coded_State : String) return State;
+
+private
+ type Int is new Interfaces.Integer_32;
+
+ -- We prefer to use 14 digits for Flt, but some targets are more limited
+
+ type Flt is digits Positive'Min (14, Long_Long_Float'Digits);
+
+ K1 : constant := 94_833_359;
+ K1F : constant := 94_833_359.0;
+ K2 : constant := 47_416_679;
+ K2F : constant := 47_416_679.0;
+ Scal : constant := 1.0 / (K1F * K2F);
+
+ type State is record
+ X1 : Int := 2999 ** 2; -- Square mod p
+ X2 : Int := 1439 ** 2; -- Square mod q
+ P : Int := K1;
+ Q : Int := K2;
+ X : Int := 1;
+ Scl : Flt := Scal;
+ end record;
+
+ type Generator is limited record
+ Gen_State : State;
+ end record;
+
+end GNAT.MBBS_Float_Random;